Arc lamp



Sept. 15, 1931. H. KOCOUREK ARC LAMP Filed April 22, 1929 v a s 14%2'1262 ya.

Patented Sept. 15, 1931 UNITED STATES HENRY KOCOUREK, OF CHICAGO, ILLINOIS ARC LAMP Application filed April 22,

The purpose of this invention is to pro vide an improved and simplified construction of an are light lamp, a principal purpose being to reduce the number of parts,

and thereby the cost of construction and assembling, and to so form the several parts that they may be securely assembled without screws or bolts, except the binding screws for the energizing circuit wires. It consists in the elements and features of construction f tion and a reflector which is shown turned 90 from assembled position.

Figure 3 is a detail section at the plane indicated by the line 3-3 on Figure 2, treating the cap member as in true position with respect to the core.

Figure 4 is a section in the same axial plane as Figure 1 showing the core and the energizing circuit wire wound as a resistance coil thereon and the carbon sockets and circuit terminals which are connected by the coil.

Figure 5 is a front elevation of a collar which forms the front end element of the casing and shields for the ventilating apertures of the reflector.

Figure 6 is a fragmentary detail in the nature of a side elevation of the core, looking in the direction of the arrow 6 on Figure 4.

Figure 7 is a fragmentary View taken substantially as a section at line, 22, on Figure 1.

Figure 8 is a section radially of the core member in a plane degrees around from that of Figure 4.

The construction shown in the drawings comprises an insulating core member which may be of porcelain, and a sheet metal casing enclosing it, and a reflector mounted at the forward end of the core, the core having 1929. Serial m.'357,04e.

at the rear end circuit terminals for engagement by a circuit plug, and having sockets for carbons between whose forward ends the lluminatin arc is formed when the lamp s energlze The core is formed with a main portion intermediate its ends, reduced in diameter, th1s intermediate portion being spirally grooved for seating the inleading energizing circuit wire which by virtue of its conductive character and length in its spiral windings about the core affords the resistance necessary for proper operation of the lamp. Referring more particularl to the drawngs, the insulating core mem er, A, has the intermediate portion of its length indicated at A reduced indiameter relatively to the rear end portion, A and the forward end portion, A which are of equal diameter;

The core has toward the rear end a diametric bore, 26, and toward the forward end a similar bore, 27, said bores being within the limits of the intermediate reduced portion of the core. The core is recessed at the rear end, at 20, 20, for holding circuit terminals, 21 and 22, which extend across the rear end bore, 26, and are insulated from each other by the intervening substance of the core, and are apertured and threaded at their exposure in the bore, 26, for binding screws, 23 and 24. At the forward end the core is recessed at 30 for carbon holdin sockets, 31 and 32, which are insulated from each other by a mica spacer, 35; these sockets extend inward across the forward bore, 27, and are bored and threaded at'their exposure in said bore for binding screws 33 and 34 respectively. The core is radially rifted at one side as seen at 28, said rift, 28, extending between and connecting the bores, 26 and 27 at one side of the axis of the core. The circuit wire constituting the resistance winding is indicated at 50, having one end secured by the binding screw, 23, to the circuit terminal, 21, and the other end secured by the binding screw, 33, to the carbon holding socket, 31, the opposite end portions of the wire being led in from the spirally wound portion to the binding screws, 23 and 33 respectively, through the diametric bores, 26

and 27 respectively. The circuit comprising the are which will be formed between the ends of the carbons is completed by wire, l0, which is entered through the rift, 28, for securement bybinding screws, 24 and 3 1 respectively, to the circuit terminals, 22, and the carbon socket, 32.

As shown, the mica spacer, 35, extends beyond the metallic carbonholding sockets, 31 and 32, at both ends of the latter, and also at the sides (as seen in Figure 7), the extension being sufficient to prevent the current from jumping across from one of said sockets to the other around the edge of he mica spacer, 85. 7 7' F or encasing the core and the cir'cuitelements thereon and therein there is provided a sheet'metal' casing. consisting of a rear end cap, B, a forward end collar, B and a perforated cylindrical body member, B said mtermedlate body member belng dimensioned for being passed onto the core over thefull dlametered end portlons for encompassing the intermediate reduced portion of the core with spacing therefrom by the amount of the reduction ofdiameter of said intermediate portion, so that there is formed.

a clear annular space around the resistance windin 's to provide for ventilation ofthe recircuit terminals, 21 and 22, protrude. At

I sistance winding as well as to prevent the liability to short-circuiting by contactwith -the casings. And for thus positioning said intermediate casing member, B it is interiorly dimensioned for fitting closely the full diametered end portions,'A and A of the core. V

The rear end cap, B, is formed as by stamp ing or spinning to fit'the form of the rear end of the core and has a central aperture, 60, registering with a recess, a, in which the its periphery the cap is formed reflexed inwardly formmg an annular shoulder, as seen at 61, and'the' mturned flange is folded at right angles to its 'int-urned direction, that i is, so as to extend longitudinally of the coreparallel to the axis and the core has a cir cumferentially extending rabbet indicated at 67 which accommodates the entire cylindrically inturnedfiange which, however, is divided into segments, 63 and 64, of which alternate segments, 63, are folded inwardly, that is, back into the plane of the inturned flange, the core being formed with a series ofnotches or rabbets, 66, alternating with projections, 65, for accommodating the infolding of said alternate segments. 'The cap, B is thus securely locked to the rear end of the core with the alternate segments 64 which were not folded into the rabbet, 66, as mentioned, constituting an interrupted cylindrical flange whose diameter is that of the unreduced end portion of the core, so that the cylindrical case member, B is adapted to telescope withsaid interrupted flange when it is slipped over the core from the forward end of the latter and thrust rearward into such telescoping engagement with the rear end cap and stopped against the annular shoulder, 61. 1

The unreduced forward end portion, A of the core is peripherally grooved as seen at 75 and Y6, and provided with notches, '77, extending across both grooves and constituting entrances to both grooves. The front end collar, B is frusto-conical in form, that is, flared from one end to the other, the smaller end having an inturned marginal flange which is interrupted by notches, 81, leaving segments, 80, between the notches, 81, for becoming engaged with said grooves. The segments, 80, are slightly oblique to the axis, while the groove, 75, lies in planes perpendicular to the axis so that when the segments, 80, are introduced through the notchcs, 81, the turningof the collar causes the oblique segments to act as cams, and the collar may be said to be screwed back against the forward end of the cylindrical casing member, B forcing the latter bacl: snugly the shoulder, 61, ofthe rear end cap.

The r ector, D, is formed at its rear open end, which is to be engaged with the core, somewhat similar to the collar B Its narrow central flange is subdivided into alnate segments, 83 and 84s, the segments 83 constituting notches and the segments 84 sioned' to enter the notches r or me core and thento engage the groove '5'6'whenthe reflector-is rotated. These lugs 84 are slightly oblique so as to'be sprung as they enterthe groove and thus secure a frictional hold in the groove 7 6 to retain the reflector in position. 1

The reflector isformed with ventilating apertures, 86, in circular arrai-iqement quite closely proximate to its engagennnt witn the core; and the collar, B in addition to the function of binding the cylindrical casing member, B between said collar and the rear cap, performs the additional function of screening the ventilating apertures of the reflector both to prevent light being emitted through the apertures'in undesired direction, and also to prevent or reduce the liability of dust and water being dashed or blown into contact with the carbons from the rear.

It is desirable to have the reflector, D,'removable so that washing or polishing it the carbons and adjacent parts will not get wet and will not interfere with free access to the interior surface of the reflector. It may a o be more convenient to pack the lamp for shipment if the reflector is removable, so that it can be telescoped over other parts of the structure. I

The cylindrical shell or casing, B is conveniently made witha lapped joint 90, secured by rivets 91, the metal being offset inwardly at One end of the piece to form this joint and thus forming an inwardly pro- )ecting rib or protrusion in the shell B This rib interlocks with a groove, 92, formed in the core member, A, and thus holds the core again'st rotation in the shell. Preferably the blank from which the shell B is made includes lugs 94 which depend from the cylindrical shell at opposite sides of the joint 90, and are perforated to receive a clamping screw 95 by which the lamp body is secured to the base 96.

I claim:

1. In a structure for the purpose indicated in combination with an insulating core body, an enclosing sheath comprising a cylindrical member dimensioned for being fast onto the core for encompassing an intermediate portion of its length; a rear end cap forwardly terminated by a cylindrical flange offset inwardly from the outer circumference of the cap, forming an annular shoulder encompassing said cylindrical flange, the latter being divided into segments of which alternate sega ments are folded inward for engaging the end cap with the core against endwise displacement, the core being recessed to accommodate the infolded segments and also having a circumferentially extending rabbet in which the cylindrical flange is seated; whereby the cylindrical case member, dimensioned as stated, is adapted to telescope over said cylindrical flange and be stopped against said encompassing shoulder.

2. In an arc lamp in combination with an insulating core body, an enclosing sheath comprising a cylindrical member dimensioned for being passed over the core body for encompassing an intermediate portion of its length, the core having a circumferentially positioned groove located a short distance back from its forward end beyond the forward end of the cylindrical case member,

- with notches entering said groove from the forward end of the core, and a front locking collar having lugs dimensioned for entering through the notches into the groove for engaging the collar with the core, said groove being positioned for causing the collar engaged therewith to stop the cylindrical sheath member and be stopped against the forward end thereof.

3. An arc lamp comprising in combination with a core consisting wholly of insulating material, a casing consisting of a rear end cap covering and bearing upon the rear end of the insulating core; a front end collar through which the core extends and is exposed forwardly, and an intermediate cylindrical member bound endwise between the cap and the collar, the cap being engaged with the insulating core at the rear end of the latter against relative longitudinal movement, and the collar being disengageably engaged with the core insulating toward the forward end of the core; whereby the insulating core is positively stopped longitudinally between said rear end cap and front end collar.

4. In'the construction defined in claim 2, the lugs of the collar being slightly oblique to the groove to act as cams against a wall of the groove for wedging the collar against the end of the cylindrical sheath member.

- 5. A construction for the purpose indicated comprising in combination with a core of insulating material, a casing consisting of a rear end cap covering the core; a front end collar exposing the core, and an intermediate cylindrical member bound endwise between the cap and the collar, the cap being engaged with the core at the rear end of the latter, and the collar being disengageably engaged with the core toward the forward end of the core, and a reflector disengageably engaged with the core at the forward end portion thereof which is within the collar forwardly of the engagement of the latter with the core.

6. A construction for the purpose indicated comprising in combination with a core of insulating material, a casing consisting of a rear end cap bearingupon and covering the rear end of the core, a front end collar bearing upon and exposing the forwardend of the core, and an intermediate cylindrical member bound endwise between the cap and the collar, the cap being engaged with the core at the rear end of the latter, and the collar being disengageably engaged with the core toward the forward end of the core, whereby the core is positively stopped longitudinally between the rear end cap and the forward end collar, the core being reduced in diameter over the main part of its length intermediate the engagement therewith of the rear end cap and the front end collar, and spirally grooved at said reduced part for seating a resistance winding,-and having toward the limits of said reduced portion diametrically extending apertures; plug-engaging circuit terminals mounted in the core at the rear end and accessible through the rear end cap for engaging a plug, said terminals being spaced apart laterally, extending across the rear diametric aperture and bored and threaded in alignment therewith for binding screws.

7. A construction for the purpose indicated comprising a core of insulating material reduced in diameter for the main portion of its length intermediate its ends, and formed at said reduced portion for seating a resistance winding; a casing enclosing the reduced part of the core dimensioned interiorly for being passed over the unreduced end portions and centralized thereby with respect to the reduced portion, whereby there is enclosed an annular space around the resistance windings seated on the reduced portion, the core being suitably recessed at the front end for accommodating carbon sockets side by" side insulated'from each a other, and at the rear end for seating ClI'Clllll terminals S1d8 by side insulated from each other,,for engagement by a circuit plug and suitably apertured for. leadin the osite ends of a resistance winding respectively from the sur-.

faceof the reduced portion to the carbon sockets and to vthe circuit terminalsat; one

side, and for accommodating a circuit completing wire connecting the carbon socket and the circuit terminal at the other side.

'8; A; construction for the purpose indicated comprising a core of insulating matefrial having proximatethe rear and front ends respectively diametric bores in the same diametric plane, and being reduced in diameter at an intermediate, portion ofoits length including the position'of said bores, and having a radial rift at'said intermediate reduced portion connectingsaid bores at one side of the access, said reduced portion being arranged for winding thereon resistance coil; the core having at the front end a centrally located recess extending in to the front end bore; carbon sockets lodged insulated from each other in said recess and extending alongside each other in said-front end bore, and having, their end portions whlch are exposed in saidfbore, bored and threaded for binding screws; "circuit terminals for plug connection mounted insulatedly in the core at the rear-end thereof extending across the rear end diametric bore provided with binding screws at their respective intersections with said here, and protruding rearwardly for enga gement by a plug; a resistance coilsecured at one end to one, of said circuit terminalsand at the other end to the, carbon socket at the same side, and acircuit completing'wire duced in diameter for themainportion of "its length intermediate its ends, and having toward the limits respectively of said reduced portion diametrically extending apertures; circuit terminals mounted in the core at the rear end and protruding forengagement of aplug, saidterminalsbeing spaced apart latorally and extending across therear diametric aperture and'bored and threaded in alignment therewith for binding screws, the core being recessed at its forwardend, and: carbon-holding sockets inserted in said recess, said sockets being insulated from-each other and having their rear ends extending across the forward diametric aperture and bored and threaded in alignment therewith foribinding screws, aresistance coil wound on T the :red'ucediportion'ofthe core, having one end extending in the rear diametric aperture and secured by abinding screw to one of the circuit terminals, the other-end extending'in thecorresponding portion of the front diametric aperture and secured by binding screw to the corresponding'carbon socket, the core having at the side opposite the binding screw 1 connections mentioned of the resistance windinga radial rift'connecting the portions of the diametric apertures at saidopposite side, and securedat its opposite ends respectively by binding screwsto the circuit terminal and the carbon socket respectively at thatgside. V v V HENRY" KOCOUREIQ 

